1. Field of the Invention
The present invention relates to the field of information transmission, and more specifically to an optical beam projector which supplies coordinate reference information to a remote receiver.
2. Description of the Prior Art
In a prior art reference issued to Girault (U.S. Pat. No. 3,398,918) two embodiments of optical systems are proposed for guiding projectiles. In the first embodiment, four fan-shaped beams are independently modulated and projected towards a target and thereby form four optical walls of a pyramidal corridor for guiding projectiles. The projectile traveling in this fashion tends to guide itself by bouncing around inside the corridor. The size of the downrange corridor is controlled by a servo driven zoom lens arrangement. In the second embodiment disclosed in the Girault reference, a proportional guidance system provides two perpendicularly oriented beams which sweep in directions perpendicular to each other in order to direct the projectile. In the second embodiment, the two beams are derived from a single light source and optically divided, respectively modulated and projected by a controlled zoom lens type system wherein the optical elements are variably oriented with respect to each other.